San Diego, Calif., Dec. 20, 2016 -- Bioengineering professor emeritus Dr. Yuan-Cheng (Y.C.) "Bert" Fung, now age 97, was a successful aeronautical engineering professor at Caltech when his mother developed acute glaucoma in 1958. He was on sabbatical in Germany that year and immersed himself in the glaucoma literature in a library near the aerodynamics research institute. He sent summaries of what he learned to his mother’s physician back in China.
“Gradually one thing became quite clear to me: the biologists do not think about what we engineers always think about—namely, the force, motion and transport phenomena. Furthermore, biology is full of interesting nonlinear problems … I found the field very attractive,” Fung said in 2000 in a wide-ranging IEEE History Center interview conducted by Frederik Nebeker.
Fung went on to found the discipline of biomechanics, which uses physics to understand the mechanical properties, structure and function of biological systems. He helped uncover fundamental biomechanics principles that affect every organ and tissue in the body, including the heart and lungs. Fung discovered, for example, that blood cells flow through capillary beds in the lung similarly to how cars meander in an underground parking garage, leading to a better understanding of microcirculation, which is the circulation of blood in the smallest blood vessels. This “sheet-flow” theory provided a quantitative description of pulmonary circulation, hypertension, edema, and respiratory distress syndrome.
Fung’s research is also central to automotive safety design—all crash tests today rely on his fundamental studies of tissue response. His Exponential Law explains how tissue deforms under stress, and problems related to severe thorax impact injuries have been solved by his “stress wave propagation” theory.
Fung grew up in mainland China, where he completed his undergraduate and master’s degrees in aeronautical engineering. He earned his doctorate at Caltech in 1948 and joined the Caltech faculty that same year. In 1966, he and Caltech colleagues Dr. Benjamin Zweifach and Dr. Marcos Intaglietta moved to UC San Diego to start the school’s bioengineering program.
From the beginning they recognized the importance of microcirculation. Zweifach worked on measuring physiological parameters in different animal models and Intaglietta invented sophisticated instrumentation, while Fung provided the mathematical theory and models that could explain the mechanics of circulation. In the process, he came up with a universal pseudoelastic law that describes the behavior of biological tissues.
Fung coined the term “tissue engineering.” He also took the first steps in developing theories that provide a mathematical framework for identifying gene expression during tissue growth in three dimensions.
“This is one of the most innovative ideas that he developed,” said Geert Schmid-Schönbein, professor and chair of the Department of Bioengineering at UC San Diego, who was Fung’s Ph.D. student.
Fung’s research provided a foundation for industrial applications in many fields, including tissue engineering of cardiovascular, musculoskeletal, gastrointestinal and cutaneous systems, and advancing products to treat burns and severe tissue injuries such as diabetic foot ulcers.
Fung has the rare distinction of being elected a member of all three National Academies: the National Academy of Engineering (NAE), Institute of Medicine, and National Academy of Sciences. He also received the President’s National Medal of Science in 2000, the NAE’s Fritz J. and Dolores H. Russ Prize, and the NAE’s Founder’s Award. He received a 2016 UC San Diego Revelle Medal and even has an asteroid named in his honor. Learn more about Y.C. Fung via the IEEE oral history at: bit.ly/BertFung